1. Risk of Exposure of Grazing Animals to Ergot Alkaloids Produced by Fungal Endophytes Glen Aiken, Ph.D. USDA-ARS Forage-Animal Production Research Unit Lexington, KY United States Department of Agriculture Agricultural Research Service

3. Tall fescue is grown on approximately 35 million acres in the eastern half of the U.S.A., making it the predominant grass utilized for grazing in the region.

4. Ergot alkaloids tightly bind α-adrenergic receptors in the vasculature to elicit persistent vasoconstriction that hinders the animal’s ability to thermo-regulate.

5. Tall fescue is a persistent and productive forage, but….. Livestock productivity, health and well-being can be compromised!!

6. Original seed for the development of ‘Kentucky 31’ seed was collected from this hillside in Menefee County, Kentucky

7. Fescue Belt

8. Claviceps fungus Infects seed and cereal of various grasses Photo by Doug Waylett

9. Claviceps can produce: Tremorgenic compounds that can cause the “staggers” conditions - excessive muscle twitching, incoordination, and convulations Ergopeptines that can induce a toxicosis similar to fescue toxicosis - produces high amounts of ergotamine.

10. Discussion